Body passageway occluder and method

ABSTRACT

An occluder, for use in a body passageway, includes a catheter and a blood flow blocking/tissue capturing element comprising structural members which define openings therebetween. The blocking/capturing element is positioned near the distal end of the catheter. The blocking/capturing element has a radially compressed insertion state and a radially expanded blocking state. The occluder also includes an actuator associated with said catheter to move said blood flow blocking element from said compressed state to said expanded state. The blood flow blocking element may have a generally funnel surface extending out from said distal end of said catheter when the blood flow blocking element is in said radially expanded blocking state. A proximal surface may be provided on the capture element, the proximal surface extending out from the distal end of the elongate tubular member wherein the tissue is captured along the proximal surface. An annular membrane may be used around said structural members of the blocking/capturing element. The annular membrane may be an annular elastomeric, impermeable membrane.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation of Tissue Removal Device andMethod, Application No. 09/819,350 filed 28 Mar. 2001, which is acontinuation of Biological Passageway Occlusion Removal, applicationSer. No. 09/189,547 filed 11 Nov. 1998, now U.S. Pat. No. 6,238,412issued May 29, 2001, which claims the priority of U.S. ProvisionalApplication, Ser. No. 60/065,118, filed on Nov. 12, 1997, thedisclosures of which are incorporated by reference.

BACKGROUND OF THE INVENTION

[0002] In general, this invention relates to a removal device for abiological occlusion and more particularly to a catheter and occlusionengaging element which is adapted to the removal of blockages inhemodialysis grafts.

[0003] There are many techniques and devices known in the art forremoving blockages in the vascular system and other passageways of thehuman body.

[0004] There is a continuing need for improved devices to meet at leastthe following objectives.

[0005] The first objective is to reduce cost. This is particularlyimportant in recent years where it is clear for safety and sanitaryreasons that these will be single use devices. A device, even though itperforms a function in some improved manner, will not be widely used ifit is considerably more costly than the alternatives available.

[0006] A second objective is to provide a device that is simple to useand in a very real sense simple to understand. This will encourage itsadoption and use by medical personnel. It will also tend to keep costlow.

[0007] The third objective is to provide a device that entails aprocedure with which the medical profession is familiar so that theskills that have been learned from previous experience will continue tohave applicability.

[0008] A fourth objective relates to the effectiveness and thoroughnesswith which the blockage is removed. It is important that a maim amountof the blockage be removed; recognizing that no device is likely toprovide one-hundred percent removal.

[0009] A fifth objective concerns safety; a matter which is often socritical as to trump the other considerations. It is important to avoidtissue trauma. In many circumstances, it is critically important toavoid breaking up a blockage in a fashion that leads to flushingelements of the blockage throughout the body involved.

[0010] There are trade-offs in design considerations to achieve theabove five interrelated objectives. Extreme simplicity and a very simpleprocedure might over compromise safety. Addressing all of theseconsiderations calls for some trade-off between the objectives.

[0011] Accordingly, an object of this invention is to provide animproved removal device for a body passageway blockage which achievesthe objectives of reduced cost, enhanced simplicity, a standardprocedure, high effectiveness and a high degree of safety. Mostparticularly, it is an object of this invention to achieve theseobjectives with an enhanced trade-off value for the combined objectives.

SUMMARY OF THE INVENTION

[0012] A first aspect of the invention is directed to an occluder foruse in a body passageway. The occluder includes a catheter, a multi-wingblood flow blocking element positioned near the distal end of thecatheter, and an actuator associated with said catheter to move saidblood flow blocking element from a radially compressed insertion stateto a radially expanded blocking state. The blood flow blocking elementhas a generally funnel surface extending out from said distal end ofsaid catheter when in said radially expanded blocking state.

[0013] A second aspect of the invention is directed to a method ofdeploying an occluder in a body passageway. The method includesinserting a catheter into a body passageway, said catheter having amulti-wing blood flow blocking element. The blood flow blocking elementis provided in a radially compressed state during the inserting step.The blood flow blocking element is radially expanded into a radiallyexpanded state extending to or near to the wall of the body passagewayafter the inserting step. The radially expanding step includes providingsaid expanded state with a generally funnel surface extending out fromsaid distal end of said catheter, and using said expanded state of saidblood flow blocking element for blocking passage of material around theoutside of said catheter.

[0014] A third aspect of the invention is directed to a method ofcapturing tissue in a body. An elongate tubular member, having a lumen,a proximal end and a distal end, is inserted into a body. Amalecot-style tissue capture element is provided in a radiallycompressed state during the inserting step. The tissue capture elementis radially expanded into a radially expanded state after the insertingstep. A proximal surface on said the capture element extends out fromthe distal end of the elongate tubular member wherein the tissue iscaptured along the proximal surface.

[0015] A fourth aspect of the invention is directed to an occluder foruse in a body passageway. The occluder includes a catheter, a blood flowblocking element comprising structural members which define openingstherebetween, the blood flow blocking element positioned near the distalend of the catheter. The blood flow blocking element has a radiallycompressed insertion state and a radially expanded blocking state. Theoccluder also includes an actuator associated with said catheter to movesaid blood flow blocking element from said compressed state to saidexpanded state. The blood flow blocking element has a generally funnelsurface extending out from said distal end of said catheter when theblood flow blocking element is in said radially expanded blocking state.

[0016] A fifth aspect of the invention is directed to method ofdeploying an occluder in a body passageway. A catheter is inserted intoa body passageway. The catheter has a blood flow blocking elementcomprising structural members which define openings therebetween and anaxially movable actuator operably coupleable to the blood flow blockingelement. The blood flow blocking element is provided in a radiallycompressed state during the inserting step. The actuator is movedthereby radially expanding said blood flow blocking element into aradially expanded state extending to or near to the wall of the bodypassageway after said step of inserting. The radially expanding stepincludes providing said expanded state with a generally funnel surfaceextending out from said distal end of said catheter. The expanded stateof said blood flow blocking element is used for blocking passage ofmaterial around the outside of said catheter.

[0017] A sixth aspect of the invention is directed to a method ofcapturing tissue in a body. An elongate tubular member, having a lumen,an actuator passing through the lumen, a proximal end and a distal end,is inserted into a body. A tissue capture element is provided in aradially compressed state during the inserting step. The tissue captureelement comprises structural members which define openings therebetween.The actuator is operably coupleable to the tissue capture element. Theactuator is moved thereby radially expanding the tissue capture elementinto a radially expanded state after the step of inserting. A proximalsurface is provided on the capture element, the proximal surfaceextending out from the distal end of the elongate tubular member whereinthe tissue is captured along the proximal surface.

[0018] A seventh aspect of the invention is directed to medicalinstrument for use in a body. The medical instrument includes anelongate tubular member, having a lumen and a distal end, and a bloodflow blocking element comprising structural members which defineopenings therebetween. The blood flow blocking element is positionednear said distal end of said elongate member. An annular membrane isaround said structural members of said blood flow blocking element. Anactuator is associated with said elongate member to move said blood flowblocking element from a radially compressed state to a radially expandedblocking state. The blood flow blocking element in said radiallyexpanded blocking state has a generally funnel shape surface extendingfrom said distal end of said elongate tubular member.

[0019] An eighth aspect of the invention is directed to an occluder foruse in a body passageway. The occluder includes a catheter, a blood flowblocking element comprising structural members which define openingstherebetween, the blood flow blocking element positioned near the distalend of the catheter, and an annular membrane around said structuralmembers of said blood flow blocking element. An actuator is associatedwith said catheter to move said blood flow blocking element from aradially compressed insertion state to a radially expanded blockingstate.

[0020] A ninth aspect of the invention is directed to a method ofdeploying an occluder in a body passageway. A catheter is inserted intoa body passageway. The catheter has a blood flow blocking elementcomprising structural members which define openings therebetween, theblood flow blocking element being covered with an annular elastomeric,impermeable membrane. An axially movable actuator is operably coupleableto a distal portion of the blood flow blocking element the blood flowblocking element is provided in a radially compressed state during saidstep of inserting. The actuator is moved thereby radially expanding saidblood flow blocking element into a radially expanded state extending toor near to the wall of the body passageway after said step of inserting.The blood flow blocking element is used in its expanded state forblocking passage of material around the outside of said catheter.

BRIEF DESCRIPTION

[0021] In brief one embodiment of this invention is particularly adaptedto the removal of blockages in hemodialysis grafts. That embodimentcombines a catheter having a blocking feature that blocks the annulusbetween the catheter and the graft and a support wire having anocclusion engaging element.

[0022] The support wire extends through the catheter, through or aroundthe occlusion and at its distal end has an annular braided elementattached thereto. The support wire is a dual element support wire havinga core and an annular shell that slides on the core. The distal end ofthe core is attached to the distal end of the annular braided elementand the distal end of the shell is attached to the proximal end of theannular braided element. Thus movement of the core and shell relative toone another moves the braided element from a radially retracted positionwhich is useful for insertion through the catheter to a radiallyexpanded position which expands it to the sidewall of the graft. Whenthe annular braided element is in its radially compressed state, it canbe passed through the occlusion together with the rest of the wire toreside on the distal end of the occlusion. When the braided element isexpanded and moved proximally (that is, in a retrograde fashion), itwill engage the occlusion and force the occlusion into the catheter.Alternatively, no motion of the engaging element may be required ifaspiration is applied. In this case, the engaging element acts as a sealto prevent the suction from aspiration to remove much material beyondits point of deployment in the channel.

[0023] The distal end of the catheter is proximal of the occlusion andcontains a blocking mechanism that extends radially from the distal endof the catheter to the wall of the graft or body passageway. Thiscatheter blocking element also has a radially retracted insertion stateand a radially expanded blocking state. The blocking element is amulti-wing malecot type device which is covered by a thin elastomericfilm or membrane.

[0024] This malecot type of device is bonded to the distal end of thecatheter or an integral part of the catheter. The distal tip of thedilator, over which the catheter is inserted, has a slightly increaseddiameter. This tip is in the nature of a ferrule. When the dilator isremoved, the ferrule abuts against the distal end of the multi-wingmalecot pushing this blocking element from its radially compressed stateinto its radially expanded state. Alternatively, the tip of the dilatorcan be bonded to the catheter with a break-away bond so that when thedilator is removed, the blocking element is expanded in a similarfashion. In this radially expanded state, the malecot and its film coverblocks the annulus around the catheter so that the occluded blood orother obstruction which is being removed is forced into the catheterwhere it is aspirated or otherwise removed.

[0025] Conversely, it is understood that the blocking element could befabricated from tubular braid and the engaging element could be formedfrom the malecot style configuration.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026]FIG. 1 is a mechanical schematic showing a device made accordingto this invention fully deployed in a plastic graft used inhemodialysis. The FIG. 1 drawing shows the blocking element at thedistal end of the catheter in its radially expanded state and theocclusion engaging element at the distal end of the support wire in itsradially expanded state. It is important to note that the blockingelement may take a variety of shapes as would be required for theparticular application. The preferred shape is likely to be a funnelshape where the larger diameter is distal to the lesser diameter that isproximal on the element. This funnel shape allows the obstruction to bemore easily accepted into the catheter due to the pull/push of theengaging element, aspiration or both.

[0027]FIG. 2 is a longitudinal view of the distal portion of the supportwire with a braided occlusion engaging element in its radial compressedstate. This is the state where the support wire and engaging element canbe inserted through the occlusion that is to be removed.

[0028]FIG. 3 shows the FIG. 2 braided occlusion engaging element in itsradially expanded state, which is the state shown in FIG. 1.

[0029]FIG. 4 shows the multi-wing malecot type blocking element at thedistal end of the catheter in its radially expanded state, which is thestate shown in FIG. 1. It should be noted that the scale of the FIG. 4catheter is much reduced compared to the scale of the occlusion removalwire and braided element shown in FIGS. 2 and 3.

[0030]FIG. 5 is a longitudinal view, in partial cross-section, showingthe catheter and dilator with a ferrule at the distal tip of the guidewire in a passageway having an occlusion that is to be removed.

[0031]FIG. 6 shows the next step in which the dilator is being removedthereby causing the malecot type blocking mechanism to become expandedby virtue of pressure against the distal end of the catheter tip of thedilator.

[0032]FIG. 7 shows the next step in which the support wire together withthe braided occlusion removal element in its radially compressed state(the state shown in FIG. 2) is inserted through the catheter and throughthe occlusion to be removed.

[0033]FIG. 8 shows the next step in which the braided occlusion removalelement has been expanded and is being pulled in a proximal directionthereby forcing the occlusion into the catheter for removal with orwithout aspiration.

[0034]FIG. 9 shows the multi-wing malecot type blocking element at thedistal end of the catheter in its radially expanded state in accordancewith another embodiment of the present invention.

[0035]FIG. 10 shows the shape of the expansion resulting from themalecot type blocking element shown in FIG. 9.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036]FIG. 1 shows a typical synthetic graft 10 used in hemodialysis.The graft extends between a vein 12 and an artery 14. The graft 10 maybe about thirty centimeters long with an inner diameter (I.D.) of 6 or 7millimeters. A catheter 16 is inserted through the wall of the graft orvessel. Typically the catheter might have an outside diameter (O.D.) of2.7 mm and an inner diameter (LD.) of 2.3 mm A malecot type expansiondevice 18 is covered with a membrane 20 (see FIG. 4). When expanded, itserves to block the annular space between the outside wall of thecatheter 16 and the graft 10. A support wire 22 for a braided removalmechanism 24 will typically have an outside diameter of about one mm andhas an internal actuator rod 26 (see FIG. 2) of approximately 0.5 mm.Because of the simplicity of the design, this outside diameter could besmaller than 0.5 mm. In FIG. 1, the malecot type blocking device 18 andthe braided removal device 24 are both shown in their expanded state andare positioned so that retrograde or proximal movement of the supportwire 22 will pull the braided element in a proximal direction to pushout whatever coagulated blood is between the braided device 18 and thedistal end of the catheter into the catheter opening where it can beaspirated; thereby clearing the blockage in the graft or other vessel.

[0037] More particular one embodiment of this invention which has beenpartly tested, was designed for use in a hemodialysis graft 10 having anI.D. of approximately six to seven mm. In that case, the catheter 16 hasa 8 French O.D. (2.7 mm) and a 7 French I.D. (2.3 mm). The support wire22 is a fairly standard movable core guide wire of 35 mils (that is,0.35 inches, which is slightly under 1 mm). The actuator rod 26 in thesupport wire is approximately 15 mils and thus slightly under 0.5 mm.The braided element 24 has an insertion diameter that is approximatelyone mm and expands to cover the seven mm diameter of the graft. In orderto achieve this seven fold increase in diameter, the braided element hasa length of 11 to 13 mm Thus the catheter has an annulus of about 2.3 mmaround the support wire, through which annulus the blood occlusion isaspirated.

[0038]FIGS. 2 and 3 illustrate the support wire 22 and braided element24 which constitute the occlusion engaging element that is movedproximal to push the occlusion into the catheter for removal. Apreferred occlusion engaging element 24 is a braided element. Thebraided material has to have a stiffness such that it will not collapseor fold under the pressure of the occlusion when this engaging elementis being moved proximally. Yet the filaments that form the braid must beflexible enough to be moved between the two states as shown in FIGS. 2and 3. Materials from polyester to stainless steel can be successfullyused. A more detailed teaching of the considerations that go into theselection of the braided engaging element is set forth fiber on.

[0039] The distal tip of the braided element 24 is connected to thedistal tip of the actuator rod 26. The proximal edge of the braidedelement 24 is bonded to the distal end of the support wire 22. Thus whenthe actuator rod 26 is pushed in a distal direction relative to the wire22, the braided device is forced into its collapsed state shown in FIG.2 and is available to be pushed through the catheter and through oraround the occlusion which is to be removed. When this engaging element24 has been fully inserted, the actuator rod 26 is moved in a proximaldirection causing the braided element 24 to take the expanded positionsuch as that shown in FIG. 3 so that subsequent movement of the entiresupport wire 22 will cause the braided element to move against theocclusion and push the occlusion into the distal end of the catheter. Insome circumstances, the braided element 24 might be left as a braid withopenings because the portions of the occlusion which may pass throughthe openings will be sufficiently smaller liquids so that they do nothave to be removed. In other circumstances, it might be desirable tocover the braided element 24 with a membrane or film so that it becomessubstantially impermeable. Further the membrane or film covering theengaging element will be helpful in preventing trauma to the inner wallsof native tissue. Even further, this membrane may be helpful in optingthe physical characteristics of the engaging element.

[0040] With reference to FIG. 1, it might be noted that when the braidedelement is pushed all the way down to one end of the graft 10, as shownin FIG. 1, and then expanded it will be expanding against a portion ofthe wall of the graft that is smaller than the bulk of the graft.However, as the support wire 22 is pulled to move the braided occlusionremoval element proximally, the braided occlusion element rides on thewall of the graft and will expand as the wall of the graft expands aslong as tension is maintained on the actuator rod 26.

[0041] There might be applications of the invention where the passagewayinvolved is a tissue passageway such as a blood vessel or other channelwithin the body, where this braided element 24 is expanded to nearly thediameter of the vessel so that when it is moved to push out anocclusion, it will avoid trauma to the wall of the vessel. Further, themembrane on the expanding element will aid in decreasing the trauma tonative vessels as described above. In such a case, the engaging element(and the blocking element) may be used only as a ‘seal’ so that theobstruction may be removed or otherwise obliterated. This seal allowsthe rest of the vessel to be uncontaminated and provides for a ‘closedsystem’ for irrigation and/or aspiration and subsequent obliteration orremoval of the obstruction

[0042]FIG. 4 illustrates the catheter 16 with the malecot 18 in anexpanded state on the distal end of the catheter. A membrane 20 isnormally used in order to provide a complete blocking or sealingfunction. Further, the membrane 20 may aid in locking the blockingelement in a particular shape. This malecot type element is created bymaking longitudinal slits in the sidewall of the catheter (or anattachment bonded thereto) thereby creating links or wings that willexpand when the distal end of the catheter is pushed in a proximaldirection. The appropriate pushing of the proximal end of the catheteris achieved, as shown in FIG. 5, by a ferrule 30 which is a standard tipon a standard dilator 28. Alternatively, the dilator 28 may be a guidewire (which is usually much longer and flexible than a dilator) forremote obstruction removal. In such an application of the presentinvention, the guide wire would have a ferrule type mechanism that wouldact like the ferrule on the dilator. In this instance, the guide wire(with ferrule) would be inserted into the vessel to the obstruction. Thecatheter would then be pushed along the guide wire until it reached theferrule which would normally be located near the distal end of the guidewire. At this point the wire would be pulled back, the ferrule wouldbutt against the catheter and force out the blocking sealing element.The engaging element may be used with this blocking element and it couldeven be the ferruled wire as well.

[0043] It should be noted that the retention catheter described in U.S.Pat. No. 3,799,172 issued on Mar. 26, 1974 to Roman Szpur illustrates astructure that is similar to the malecot type device 18 illustrated inFIG. 4; although in that patent it is used as a retention device whereasin this invention it is used as a blocking element.

[0044] This blocking element 18 is often called a malecot in theindustry. It should be understood herein that the term malecot is usedto refer in general to this type of multi-wing device.

[0045] More specifically, as shown in FIG. 5, the catheter 16 togetherwith a dilator 28 having an expanded tip 30 which is a ferrule isinserted into a vessel 32 such as the graft shown in FIG. 1. Thecatheter 16 and dilator 28 are inserted close to the occlusion 34 andthen the dilator 28 is removed. Proximal motion of the dilator 28 causesthe tip 30 to contact the distal end of the catheter 16 forcing thedistal end of the catheter to put pressure on the malecot wings creatingthe expansion shown in FIG. 6 (and also schematically shown in FIG. 1).Once this expansion has occurred, the dilator with its tip can beremoved from the catheter (as shown in FIG. 6).

[0046] What then occurs is shown in FIGS. 7 and 8. As shown in FIG. 7,the support wire 22 with its braided removal element 24 is inserted inthe collapsed state so that it passes through or around the occlusion34. It should be noted that the support wire 24 may be inserted prior tothe blocking catheter being inserted or after the catheter is inserted(the latter of which is illustrated in the figures). Most of theocclusions to which this invention is directed such as congealed bloodin a graft will permit a support wire 22 to pass through it because theconsistency is that of viscous material which can be readily penetrated.Alternatively, if the occlusion is a non viscous material such as astone, plaque, emboli, foreign body, etc. the support wire 22 is smallenough to be passed around the occlusion. Once the braided element 24 ison the distal side of the occlusion 34, the actuator rod 26 is pulledcreating the expanded state for the braided device. Accordingly, distalmovement of the entire support wire will cause the expanded braideddevice to move against the occlusion and force it into the catheter forremoval with or without aspiration. When removal of obstructions thatare located some distance array from the point of access into the bodysuch as the carotid artery via a groin access the wire 22 would likelybe inserted first. In this case the support are 22 with its expandingelement 24 may be used as a guide wire to guide the catheter to thepreferred location. Of further import is that the blocking element andthe engaging element may be used without any relative motion oncedeployed. Such is the case when irrigation and/or aspiration is used forthe obstruction removal In this case the two elements can be used asseals against the tubular inner walls on both sides of the obstructionwhereby the obstruction is removed from that ‘sealed’ space with the useof aspiration, irrigation, or both. Further other means of obliteratingthe obstruction within this ‘sealed’ space may be employed. Some ofthose means are, but are not limited to the addition of dissolvingagents, delivery of energy such as ultrasound, laser or light energy,hydraulic energy and the like.

[0047] The Tubular Braid Engaging Element

[0048] The engaging apparatus includes an elongate tube; an elongatemandril inside the tube and an expandable tubular braid. The elongatemandril extends from the proximal end of the device to the distal end.The elongate tube extends from close to the proximal end of the deviceto close to the distal end. The distal end of the tubular braid isbonded to the distal end of the inner elongate mandril. The mandril mayextend beyond the tubular braid. The proximal end of the tubular braidis bonded to the distal end of the elongate tube.

[0049] The braid may be open, but may be laminated or covered with acoating of elastic, generally inelastic, plastic or plasticallydeformable material, such as silicone rubber, latex, polyethylene,thermoplastic elastomers (such as C-Flex, commercially available fromConsolidated Polymer Technology), polyurethane and the like. Theassembly of tube, mandril and braid is introduced percutaneously in itsradially compressed state. In this state, the outside diameter of thebraid is close to the outside diameter of the elongate tube. Thisdiameter is in the range of 10 to 50 mils, and usually 25 to 40 mils(i.e. thousandth of an inch). After insertion, the tubular braid isexpanded by moving the mandril proximally with respect to the tube.

[0050] The tubular braid is preferably formed as a mesh of individualnon-elastic filaments (called “yarns” in the braiding industry). But itcan have some elastic filaments interwoven to create certaincharacteristics. The non-elastic yarns can be materials such aspolyester, PET, polypropylene, polyamide fiber (Kevlar, DuPont),composite filament wound polymer, extruded polymer tubing (such as NylonII or Ultem, commercially available from General Electric), stainlesssteel, Nickel Titanium (Nitinol), or the like so that axial shorteningcauses radial expansion of the braid. These materials have sufficientstrength so that the engaging element will retain its expanded conditionin the lumen of the body while removing the obstruction therefrom.

[0051] The braid may be of conventional construction, comprising roundfilaments, flat or ribbon filaments, square filaments, or the like.Non-round filaments may be advantageous to decrease the axial forcerequired for expansion to create a preferred surface area configurationor to decrease the wall thickness of the tubular braid. The filamentwidth or diameter will typically be from about 0.5 to 25 mils, usuallybeing from about 5 to 10 mils. Suitable braids are commerciallyavailable from a variety of commercial suppliers.

[0052] The tubular braids are typically formed by a “Maypole” dance ofyarn carriers. The braid consists of two systems of yarns alternatelypassing over and under each other causing a zigzag pattern on thesurface. One system of yarns moves helically clockwise with respect tothe fabric axis while the other moves helically counter-clockwise. Theresulting fabric is a tubular braid. Common applications of tubularbraids are lacings, electrical cable covers (i.e. insulation andshielding), “Chinese hand-cuffs” and reinforcements for composites. Toform a balanced, torque-free fabric (tubular braid), the structure mustcontain the same number of yarns in each helical direction. The tubularbraid may also be pressed flat so as to form a double thickness fabricstrip. The braid weave used in the tubular braid of the presentinvention will preferably be of the construction known as “twodimensional, tubular, diamond braid” that has a 1/1 intersection patternof the yarns which is referred to as the “intersection repeat”.Alternatively, a Regular braid with a 2/2 intersection repeat and aHercules braid with an intersection repeat of 3/3 may be used. In allinstances, the helix angle (that being the angle between the axis of thetubular braid and the yarn) will increase as the braid is expanded. Evenfurther, Longitudinal Lay-Ins can be added wit the braid yarns andparallel to the axis to aid with stability, improve tensile andcompressive properties and modulus of the fabric. When theselongitudinal “Lay-In” yarns are elastic in nature, the tubular braid isknown as an elastic braid. When the longitudinal yarns are stiff, thefabric is called a rigid braid. Biaxially braided fabrics such as thoseof the present invention are not dimensionally stable. This is why thebraid can be placed into an expanded state from a relaxed state (in thecase of putting it into the compressive mode). Alternatively this couldbe a decreased/reduced (braid diameter decreases) state when put intotension from the relaxed state. When put into tension (or compressionfor that matter) the braid eventually reaches a state wherein thediameter will decrease no more. This is called the “Jammed State”. On astress strain curve, this corresponds to increase modulus. Much of theengineering analysis concerning braids are calculated using the “Jammedstate” of the structure/braid. These calculations help one skilled inthe art to design a braid with particular desired characteristics.Further, material characteristics are tensile strength, stiffness andYoung's modulus. In most instances, varying the material characteristicswill vary the force with which the expanded condition of the tubular canexert radially. Even further, the friction between the individual yarnshas an effect on the force required to compress and un-compress thetubular braid. For the present invention, function should be relativelylow for a chosen yarn so that the user will have little troubledeploying the engaging element. This is particularly important when theengaging element is located a significant distance from the user. Suchis the case when the percutaneous entry is the groin (Femoral Artery forvascular interventions) and the point of engaging the engaging elementis some distance away (i.e. the Carotid Artery in the neck). Similarly,this is true for long distances that are not vascular or percutaneousapplications.

[0053] Other Comments

[0054] An important consideration of the invention described herein isthat the support wire with its expanding element can be fabricated witha very small diameter. This is important because it allows an optimallylarge annular space between the wire and the inside of the catheter formaximum obstruction removal. Previous engaging elements have been usedthat use a balloon for the engaging element. This balloon designrequires a larger shaft diameter than that of the present invention.Hence in these previous devices the annular space is not maximized as inthe present invention. The term wire is used to refer to the supportportion of the removal device. The material of the wire need notnecessarily be-metal. Further, it may be desirable to use a ‘double’engaging element (i.e. two braided or malecot expanding elementsseparated a distance appropriate to entrap the occlusion) in the casefor example where the occlusion is desired to be trapped in the vessel.The term wire is used herein to refer to a dual element device having ashell component and a core or mandril component which are longitudinallymoveable relative to one another so as to be able to place the braidedocclusion engaging element into its small diameter insertion state andits large diameter occlusion removal state.

[0055] Although the blocking element is described as a multi-malecottype of device, it should be understood that the blocking element may bedesigned in various fashions which are known in the art. See, forexample, FIGS. 9 and 10. As another example, an appropriately designedbraid arrangement could be used as the blocking element. In that case,the catheter may have to be a dual wall catheter in which the inner andouter annular walls are able to move relative to one another in alongitudinal direction so as to place the braid used as a blockingelement in its small diameter insertion state and its large diameterblocking state. Alternatively, it may be a single wall similar in designto the malecot style blocking element described previously.

[0056] The particular embodiment disclosed was designed for anapplication to remove congealed blood in a dialysis graft. For someapplications, like removing clots from remote vascular areas, theblocking mechanism and engaging elements may be used only as distal andproximal seals around the device to be removed so that the clot or otherobstruction can be removed with aspiration or can be obliterated withsome therapy such as a chemical dissolving agent or acoustical energy orlithotripsy and the like. The residual obstruction in that case would beaspirated from the tubular catheter.

[0057] It should be further understood that there might be a situationin which the blocking element or even the occlusion engaging elementwould be provided to the physician in a normal expanded state so thatwhen the device is deployed, it would, through plastic memory or elasticmemory, automatically snap into its expanded state.

1. An occluder for use in a body passageway comprising: a catheterhaving a distal end, a multi-wing blood flow blocking element positionednear the distal end of the catheter, said multi-wing blood flow blockingelement having a radially compressed insertion state and a radiallyexpanded blocking state, an actuator associated with said catheter tomove said blood flow blocking element from said compressed state to saidexpanded state, and said blood flow blocking element in said radiallyexpanded blocking state having a generally funnel surface extending outfrom said distal end of said catheter.
 2. The occluder of claim 1further comprising an annular membrane around said wings of said bloodflow blocking element.
 3. The occluder of claim 1 wherein said multiwingblood flow blocking element is a malecot style device.
 4. The occluderof claim 2 wherein said membrane is an elastomeric, impermeablemembrane.
 5. The occluder of claim 1 wherein said actuator extends,through said lumen, distal of said blood flow blocking element and whenmoved in a proximal direction, engages said blood flow blocking elementto switch said blood flow blocking element from said retracted insertionstate into said radially expanded blocking state.
 6. The method ofdeploying an occluder in a body passageway comprising: inserting acatheter into a body passageway, said catheter having a multi-wing bloodflow blocking element, providing said blood flow blocking element in aradially compressed state during said step of inserting, radiallyexpanding said blood flow blocking element into a radially expandedstate extending to or near to the wall of the body passageway after saidstep of inserting, said step of radially expanding including providingsaid expanded state with a generally funnel surface extending out fromsaid distal end of said catheter, and using said expanded state of saidblood flow blocking element for blocking passage of material around theoutside of said catheter.
 7. The method according to claim 6 whereinsaid blood flow blocking element is a malecot-style blood flow blockingdevice covered with an annular elastomeric, impermeable membrane.
 8. Amethod of capturing tissue in a body comprising: inserting an elongatetubular member, having a lumen, a proximal end and a distal end, into abody, providing a malecot-style tissue capture element in a radiallycompressed state during the step of inserting, radially expanding thetissue capture element into a radially expanded state after the step ofinserting, and providing a proximal surface on said the capture element,the proximal surface extending out from the distal end of the elongatetubular member wherein the tissue is captured along the proximalsurface.
 9. The method according to claim 8 wherein the tissue captureelement is generally funnel shaped when in the radially expanded state.10. An occluder for use in a body passageway comprising: a catheterhaving a distal end, a blood flow blocking element comprising structuralmembers which define openings therebetween, the blood flow blockingelement positioned near the distal end of the catheter, said blood flowblocking element having a radially compressed insertion state and aradially expanded blocking state, an actuator associated with saidcatheter to move said blood flow blocking element from said compressedstate to said expanded state, and said blood flow blocking element insaid radially expanded blocking state having a generally funnel surfaceextending out from said distal end of said catheter.
 11. The occluder ofclaim 10 further comprising an annular membrane around said structuralmembers of said blood flow blocking element.
 12. The occluder of claim11 wherein said blood flow blocking element is a malecot style device.13. The occluder of claim 11 wherein said membrane is an elastomeric,impermeable membrane.
 14. The occluder of claim 10 wherein said actuatorextends, through said lumen, distal of said blood flow blocking elementand when moved in a proximal direction, engages said blood flow blockingelement to switch said blood flow blocking element from said retractedinsertion state into said radially expanded blocking state.
 15. A methodof deploying an occluder in a body passageway comprising: inserting acatheter into a body passageway, said catheter having a blood flowblocking element comprising structural members which define openingstherebetween and an axially movable actuator operably coupleable to theblood flow blocking element, providing said blood flow blocking elementin a radially compressed state during said step of inserting, moving theactuator thereby radially expanding said blood flow blocking elementinto a radially expanded state extending to or near to the wall of thebody passageway after said step of inserting, said step of radiallyexpanding including providing said expanded state with a generallyfunnel surface extending out from said distal end of said catheter, andusing said expanded state of said blood flow blocking element forblocking passage of material around the outside of said catheter. 16.The method according to claim 15 wherein said blood flow blockingelement is a malecot-style blood flow blocking device covered with anannular elastomeric, impermeable membrane.
 17. A method of capturingtissue in a body comprising: inserting an elongate tubular member,having a lumen, an actuator passing through the lumen, a proximal endand a distal end, into a body, providing a tissue capture element in aradially compressed state during the step of inserting, the tissuecapture element comprising structural members which define openingstherebetween, the actuator operably coupleable to the tissue captureelement, moving the actuator thereby radially expanding the tissuecapture element into a radially expanded state after the step ofinserting, and providing a proximal surface on said the capture element,the proximal surface extending out from the distal end of the elongatetubular member wherein the tissue is captured along the proximalsurface.
 18. The method according to claim 17 wherein the tissue captureelement is generally funnel shaped when in the radially expanded state.19. A medical instrument for use in a body comprising: an elongatetubular member having a lumen and a distal end, a blood flow blockingelement comprising structural members which define openingstherebetween, the blood flow blocking element positioned near saiddistal end of said elongate member, an annular membrane around saidstructural members of said blood flow blocking element, said blood flowblocking element having a radially compressed state and a radiallyexpanded blocking state, an actuator associated with said elongatemember to move said blood flow blocking element from said compressedstate and to said blocking state, said blood flow blocking element insaid radially expanded blocking state having a generally funnel shapesurface extending from said distal end of said elongate tubular member.20. The medical instrument of claim 19 wherein said membrane is anelastomeric, impermeable membrane.
 21. The medical instrument of claim19 wherein said actuator extends, through said lumen, distal of saidblood flow blocking element and when moved in a proximal direction,engages said blood flow blocking element to switch said blood flowblocking element from said retracted compressed state into said radiallyexpanded state.
 22. An occluder for use in a body passageway comprising:a catheter having a distal end, a blood flow blocking element comprisingstructural members which define openings therebetween, the blood flowblocking element positioned near the distal end of the catheter, and anannular membrane around said structural members of said blood flowblocking element, said blood flow blocking element having a radiallycompressed insertion state and a radially expanded blocking state, anactuator associated with said catheter to move said blood flow blockingelement from said compressed state to said expanded state.
 23. Theoccluder of claim 22 wherein said membrane is an elastomeric,impermeable membrane.
 24. The occluder of claim 22 wherein said actuatorextends, through said lumen, distal of said blood flow blocking elementand when moved in a proximal direction, engages said blood flow blockingelement to switch said blood flow blocking element from said retractedinsertion state into said radially expanded blocking state.
 25. Themethod of deploying an occluder in a body passageway comprising thesteps of: inserting a catheter into a body passageway, said catheterhaving a blood flow blocking element comprising structural members whichdefine openings therebetween, the blood flow blocking element coveredwith an annular elastomeric, impermeable membrane, and an axiallymovable actuator operably coupleable to a distal portion of the bloodflow blocking element, providing said blood flow blocking element in aradially compressed state during said step of inserting, and moving theactuator thereby radially expanding said blood flow blocking elementinto a radially expanded state extending to or near to the wall of thebody passageway after said step of inserting, and using said expandedstate of said blood flow blocking element for blocking passage ofmaterial around the outside of said catheter.
 26. The method of claim 25wherein said step of radially expanding includes providing said expandedstate with a generally funnel surface extending out from said distal endof said catheter.
 27. The method of claim 25 wherein the actuator movingstep comprises proximally pulling the actuator.